The final six miles to 162nd Avenue/Colorado Highway 7 will be built as funds become available. Once completed, the line will run from downtown Denver through north Denver, Commerce City, Thornton and Northglenn to northern Adams County.

During the groundbreaking, RTD General Manager and Chief Executive Officer Phil Washington noted that 2014 marks the 20-year anniversary of rail transit opening in Denver and the 10-year anniversary of voters' approval of the FasTracks expansion program to build 122 miles of new passenger rail and bus rapid transit across RTD's eight-county district.

"It's remarkable to see how far we've come," Washington said. "More than a year ago, this line was not set to be completed for many years. Now, because of innovative financing, working with our stakeholders and reaching out to the private sector, we are here today breaking ground on the first phase of the North Metro Rail Line."

Other RTD FasTracks rail lines under construction are the East Rail Line to Denver International Airport; the Gold Line to Arvada and Wheat Ridge; the I-225 Rail Line in Aurora and the first segment of the Northwest Rail Line to Westminster, which are all scheduled to debut in 2016.